Photographic bleaching out of azomethine and azoaniline dyes



United States Patent 3,503,744 PHOTOGRAPH-11C BLEACHING OUT OF AZOMETHINE AND AZOANILINE DYES Kohei Itano, Masashi Nakano, and Shoichiro Hoshino,

Tokyo, Japan, assignors to Keufiel & Esser Company,

Hoboken, N.J., a corporation of New Jersey N0 Drawing. Filed Feb. 16, 1967, Scr. No. 616,503

Int. Cl. G03c 1 72, 5/24 US. Cl. 9689 8 Claims ABSTRACT OF THE DISCLOSURE Material for preparing permanent photocopies comprises a color modifier and an organic halogen-containing compound capable of producing free radicals upon exposure to light to react with said color modifier to produce a color change, said color modifier being an azoaniline or azomethine dye of the general formula wherein R and R are alkyl or hydroxyalkyl;

R is hydrogen, alkyl, amino, or substituted amino;

is a keto-methylene group, pyrazolone group, or a nucleus having an active hydrogen-containing coupler component.

Imagewise exposure of the material to light provides a like distribution of reactive halogen free radicals which have a bleaching effect on the color modifier and results in image formation. The image may be fixed by heating acidic anhydrides incorporated in the material or by washing the material to remove at least one of the color modifier or organic halogen compounds.

The present invention relates to making photocopies and particularly to providing a stable color modifier which may react with an initiator to produce a visible image in accordance with a light pattern and more particularly relates to a bleaching-out process where the light-struck portions of the light-sensitive materials are rendered colorless leaving the portions of the photosensitive material which have not been struck by light in their colored form.

Heretofore, various photosensitive compositions have been used including some dyes, but the prior materials and methods have not been entirely satisfactory since the dyes would bleach out after a period of time, rendering the copy unusable.

An object of the present invention is to provide a photocopy material and method whereby permanent copies can be made with actinic light.

As a color-modifier which is free from the above-mentioned drawbacks, the present invention uses a compound of the following general formula:

(wherein R and R individually mean alkyl or hydroxyalkyl; R means hydrogen, alkyl or amino group optionally substituted;

is a ketomethylene group or pyrazolone nucleus or the 3,503,744 Patented Mar. 31, 1970 ice.

residue of an active hydrogen-containing coupler component, e.g. phenols).

The above compound which is used in the invention has found its application in color films and photographic papers and it is recognized as such a dye which is formed by color development of the color film or photographic paper with a color developer of the diethyl-p-phenylenediamine type after light exposure. Accordingly, the lightsensitive material of the present invention which uses the above-said dye does not suffer from color image fading which is encountered in the prior art. The light-fastness of the printing material of the invention is practically satisfactory. For instance, no fading is observed when the color image on the printing material is subjected to irradiation from a carbon arc lamp at a distance of 45 cm. at a temperature of 50 C. under a relative humidity of 45% for 8 hours in a fading-out tester.

Thus, the colored image formed on the light-sensitive material of the invention is remarkably excellent in lightfastness. The compounds which are usable in the invention can be prepared with relative ease.

Typical illustration of the compounds having the abovedefined general formula will be given below, without limiting the scope of the invention thereto. It is to be noted that the homologous compounds which are generally known in the color photographic art also are efiective for the purpose of the present invention.

Benzoyl- (p-diethylaminophenylimino -acetanilide omoQo-o: @Nwmm Yellow dye p Methoxybenzoyl (p diethylamino o methylphenylimino) acetanilide HO O C IYL-C H l Yellow dye p Stearoylaminobenzoyl (p diethylaminophenylimino) aceto- (m,m-dicarboxy) -anilide l I 35011 0 H000 HOOJJ Yellow dye Benzoyl(p diethylamino o methylphenylirnino) aceto-n-stearyl- (m-carboxy -anilide Cyano- (p-diethylamino-phenylimino) acetoanilide (18) O H C-N-C17Hzl y CONH (kHz Cyan dye I 2-carbo-(2'-N-methyl-N-stearylamino-5-carboxyphenyl)- aniline-4-(p-diethylamino-o-methylphenylimino) naphthoquinone 0 H2 O1 -NHCOOH:O v CH2-C(CH:;)3 20 I I- N 0 H) 2 chloro-4-(p diethylaminophenylimino)-6-(2,4-di-tert.

amylphenoxy-acetoamino)benzoquinone I y NN(C2Hs)fl Cyandye I 4(p-diethylaminophenylimino)-8-quinolinone 40 v Cm 4-(p-diethylamino-o-methanesulfoamino-phenylimino) naphthoquinone Being exposed to light, especially to ultraviolet ray, these compounds are bleached by the action of a photoinitiator capable of generating a reactive-free halogen radical, thereby to leave a colored image in the unex- 0 posed areas. As typical photoinitiators usable for this purpose, the following compounds are mentioned:

( 1) Carbon tetrabromide CB1;

(2) Pentabromotoluene C HBr (3) Bromoform HCBr (4) Iodoform H01 (5) 1,1,1-trichloro-3-propanol Cl C-CH CH OH (6) 2,2,2-tribromoethano1 Br CCH OH (7) Dichlorobromoethane Cl BrCH 8 p,p-Dichlorodiphenyl-2,2,2-tribromoethane (9) tDiphenyl-2,2,Z-trichloroethane 13 C $01, 2 (10) p-Nitroa,a,a-tribromotoluene C B I; (11 a,a,a-Trichloroluene CCla (13) Trichloracetoamide Cl CCNH (14) Chloral hydrate Cl CCOH-H O (14) w,w,w-Tribromoquinaldine BnC \N/ (16) 4-phenyl-6-w,w,w-tribromopyrimidine The light-sensitive, printing material of this invention can be obtained by producing a solution which contains the above mentioned color modifier and photo-initiator together with a suitable high molecular binder capable of forming film and spreading the resulting solution on a supporting material such as paper or film base. As the high molecular binder, various compounds, for example, cellulose derivatives such as acetylcellulose, ethylcellulose, etc., polymeric vinyl compounds such as polyvinyl chloride, polyvinyl acetate, polyvinylidene chloride, polystyrene, etc., or synthetic rubbers such as styrene-maleic anhydride copolymer, cyclized rubber, butadiene-copolymer can be used, As a solvent, such solvent may be selected that can thoroughly dissolve the binder used. For example, a solvent such as acetone, methyl ethyl ketone, ethyl acetate, butyl acetate, dioxane, cyclohexanone, etc. and a mixed solvent such as acetone-methanol, acetonebenzene, etc. can be mentioned.

According to the present invention, a sensitizer can be ,added as an auxiliary component and the bleaching action can be elfected by the action of light having specific range of wave length, and so the colored image can be prepared by forming multi-layers of several kinds of color modifiers and then bleaching each of the layers by the action of light having specific wave length. As such sensitizer usable for this purpose, a sensitizing dye used for photography such as cyanine, merocyanine, styryl or acridine dye can efiectively be used. Following dyes are the examples of the sensitizing dyes:

Acridine Orange, Acridine Red, Rose Bengal, Methylene Blue, Pinacyanol, Pinakryptol Yellow.

1- [3-ethyl-2-( 3H -benzothiazolidene] -4-'buty1idenedibenzothiazolyl methane,

[ 1-ethyl-4'( 1H) -quinolidene] -ethylidene-di-Z-benzothiazolyl methane, 7

5,2, 3-ethyl benzoxolidene) -ethylidene-2-phenylimi110-3- phenyl-4-keto-tetrahydrothiazole,

1,3-diethylthia-4'-carbocyanine iodide,

1,3-dimethy1 oxa-Z-carbocyanine-ptoluene sulfonate,

5, 1-methyl-2( 1H) -quinolidene-2 butylidene-3 -ethyl-2- thio-2,4-oxazolidene dione.

Very small amount of the sensitizing dye is thoroughly added.

Moreover, in order to improve the stability of image and developing property, about 1%, based on the lightsensitive solution, of lead oxide, titanium dioxide, starch, etc. may be added.

The fixing of the light-sensitive, printing materiahof this invention is effected by heating said material after it has been printed or by subjecting the material to the treatment with solvent. When the fixing is effected by the heating method, a heat-fixing agent might have been added previously, if necessary. As the heat-fixing agent, anhydrous acids such as phthalic anhydride, maleic anhydride, succinic anhydride or organic acids such as ben-. zoic acid, phenylacetic acid, phenoxy-acetic acid, phthalaldehydic acid, palmitic acid, stearic acid, etc. are effective. These heat-fixing agents can be added to the binder solution together with the' photo-initiator and the color modifier. Besides the above acids, salts such as sodium metaborate, sodium carbonate, sodium salicylate, sodium oxalate, etc. are also eflective, but these salts cannot be added to the binder solution and so they are overcoated on the surface of the light-sensitive layer of the 1ightsensitive, printing material of this invention as an aqueous solution containing about 0.5% of the salts.

The light-sensitive, printing material of this invention can be produced according to the known method by dissolving each of the aforementioned components in the binder solution and coating the resulting solution on a suitable supporting material. The' preferable quantitative ratio of each of the above components is roughly limited as follows:

To 100 parts (by weight) of solvent; 5-10 parts of binder, 0.1-10 parts of color modifier, 1-15 parts of photo-initiator.

As the supporting material, although any of paper, plastic film base, glass plate and metal plate may be used, generally, a clear image of good resolving power and high density can be obtained, when a photographic paper or plastic-coated paper is used as the supporting material. Furthermore, when a photographic film base is used, a clear transparent image can be formed. In general, it is most preferable to coat the light-sensitive layer on the supporting material in such amount that the thickness of the light-sensitive layer may be' about 2-3,u.

A clear image can be produced when the light-sensitive, printing material of this invention thus obtained is exposed through :an original thereby to eifect imagewise bleaching of a dye. However, since' it is impossible to keep an image in ambient light, the image must be fixed. The fixing of an image is effected by stabilizing the residual photo-initiator by heating the printed material or by removing the residual photo-initiator by treating with a suitable solvent. The above heating method may be carried out by means of heating rollers, hot plates, etc. having a surface temperature of about 80-150 C. for about 0.5-2 minutes. In fixing with a solvent, such solvent that does not dissolve the residual dye but dissolves olfthe photo-initiator, is selectively used. Generally, the treatingperiod of 1 5 minutes is suificient for fixing with a solvent and a stable image' can be obtained thereby. As such solvent, the mixed solvent comprising trichloro- 8 ethylene, ethyl acetate, and cyclohe'xane is suitable andefiective. I, p p

The following examples illustrate the present invention:

EXAMPLE 1 P On a photographic paper whichhad previously been treated on the surface with 1l.5 g./m. of polyvinyl alcohol having the polymerization, degree of about 600, cc./m. of the light-sensitive solution having thefollowing composition was coated. under yellow safe light lamp and dried to give alight-sensitive, printing material:

Acetone,50 cc. Methanol -5.0 "Co. I

- cellulose'acetate w g Benzoyl-(1-diethylamino-phenylimino)-acetanilide [Color Modifier (1) as abqve]1 g. 4-w,w,w-tribromomethyl pyrimidine10 g.

An original was put on the light-sensitive, printing material and the asse'mblywas exposed with a 600 W- mercury lamp for 5 seconds'at 5 cm. distance therefrom. Thus, a yellow image was formed. This imagewas converted into a stable image according to the fixing with solvent by dipping the light-sensitive material having said image in the mixed solvent of ethyl acetate and cyclohexane (50:50) for 3 minutes.

EXAMPLE '2 p I 10 g. of cellulose acetate was dissolved in 100 cc. of

' an acetone-benzene (40:60) mixture, and then the mixture of 2.5 g. of w-cyano-w-(p-diethylamino-o-methyl-phenylimino) aceto (p-N-octadece'nyl succinyl amino) phenone [Color Modifier (9) as above] and 10- g. of carbon tetrabromide was dissolved therein. In an analogous manner to the Example 1, this solution was coated on a photographic paper.whichhad previously been treated as Example 1.

Being exposed analogouslyto the Example 1, a clear red image was formed. A stable image was prepared by treating said image with a heat roller having surface temperature of C. for 1 minute.

EXAMPLE, 3

10 g. of cellulose acetate was dissolved in cc. of an acetone-benzene (50:50) mixture, and then the mixture of 2 g. of 2-chloro-4-(p-diethylarnino-phenylimino) naphthoquinone and 10 g of w,w,w-tribromoquinaldine was dissolved therein. This solutionwas coated on a photographic paperwhich had previously been treated analogously to the Example l in such amount that 15 cc./m. of the solution were coated and the photographic paper was dried. An. original was put on the resulting light-sensitive material and the assembly was exposed with a slide projector equipped with a 500 W-projecting lamp as the light source forS minute's. Thus, a clear blue image was formed. Being dipped in an ethyl acetate-cyclohexane (1:1) mixturefor 3; minutes, this image was converted into a stable. image which did not show any change towards light. 1

EXAMPLE 4 10 g. of cellulose acetate were dissolved in 100 cc. of an acetone-benzene (50:50) mixture, and then the mixture of 0.2 g. of p-me'thoxybenzoyl-(p-diethylaminophenylimino)-acetanilide [Color Modifier (2) as above], 0.3 g. of 1-phenyl-3-methyl 4 (p-diethylaminophenylimino)-S-pyrazolone, 0.35 g. of 2-carboxyanilino-4-(pdiethylaminophenylimino) naphthoquinone and 10 g. of carbon tetrabromide was dissolved therein. This solution was printed on the baryta paper analogously to the Example 1 and was dried. 1 f

Be'ing exposed with the slide projector same as that used in the Example 3, a clear white and black image was obtained. The light-sensitive material having this image was converted into a completely stable image when it was treated by wet fixing method analogous to that effected in the Example 3. A stable image was also obtained when said white and black image was treated with heat rolls having surface temperature of 100 C. for 1 minute.

EXAMPLE On the transparent film of cellulose triacetate of 14/ 1000 mm. thickness, ml./m. of the light-sensitive solution which had the following composition were coated as a first layer:

Acetone-50 cc.

Methanol-50 cc.

Nitrocellulose-l0 g.

p-Stearoylaminobenzoyl-(p-diethyl-amino phenylimino) aceto(m,m-dicarboxy) anilide [Color Modifier (3) as above]-0.3 g.

3,3 diethyl 4 methyloxythiazolocarbocyanine iodide- Caron tetrabromide-IO g.

After the first layer was dried, a light-sensitive solution having the following composition was analogously coated thereon as a second layer:

Acetone-50 cc.

Methanol50 cc.

Nitrocellulose-10 g.

w-Cyano w (p-diethylaminophenylimino) aceto (p-octadecenyl succinylamino)phenone0.2 g.

1-3'-dimethyloxy-Z-carbocyanine p toluene sulfonate Carbon tetrabromide10 g.

Further, on the second layer, a light-sensitive solution having the following composition was analogously coated as a third layer:

Acetone50 cc.

Methanol-50 cc.

Nitrocellulose-1O g.

2-carboxystearylamino 4 (p-diethylaminophenylimino) naphthoquinone0.4 g.

1,1-dimethyl-2,2-dicarbocyanine p toluene sulfonate-- Carbon tetrabromide-10 g.

The light-sensitive film thus formed in tri-pack Was divided into four sections. Each of the four sections was exposed with a 500 W-refiective photoflood lamp at 10 cm. distance for 1 minute, the first section through Kodak Wratten filter #49 (blue filter), the second section through Kodak Wratten filter #61 (green filter), the third section through Kodak Wratten filter #29 (red filter) and the fourth section Without any filter, and dipped for 3 minutes in ethyl acetate-cyclohexane (1:1). Each of the sections was colored to a tint corresponding to that of the filter used, that is, the first section to blue, the second section to green, the third section to red and the fourth section to achromatic. These colors were entirely stable after being exposed again.

From the above description, it will be apparent that an effective light-sensitive printing material of organic compound has been provided to form permanent copies from a master after exposure to light and fixing.

It will be apparent that changes may be made in the invention within the spirit thereof and the valid scope of the claims.

The above examples have been presented for the purpose of illustration and should not be taken to limit the scope of the present invention. It will be apparent that the described examples are capable of many variations and modifications which are likewise to be included within the scope of the present invention as set forth in the appended claims.

What is claimed is:

1. A light-sensitive printing material containing a color modifier and an organic halogen-containing compound capable of producing free radicals upon exposure to light to react with said color modifier to produce a color change, said color modifier being an azoaniline or azomethine dye of the general formula:

wherein R and R are alkyl or hydroxyalkyl; R is hydrogen, alkyl, amino, or substituted amino;

is a keto-methylene group, pyrazolone group, or a nucleus having an active hydrogen-containing coupler component.

2. The invention according to claim 1 wherein the color modifier compound is selected from the group of compounds identified as Formulas 1 through 21 inclusive of the specification.

3. The invention according to claim 1 in which the initiator is selected from the group of photo-initiators identified as Formulas 1 to 16 inclusive of the specification.

4. A photo-sensitive element comprising a base sheet coated with the color modifier and initiator according to claim 1.

5. A multi-color photo-sensitive element comprising a base sheet having a plurality of separate layers of the material according to claim 1 [with each layer including a different color modifier whereby light passing through a selected filter will affect only one color modifier compound in one layer and such layer can be fixed thereafter and whereby light passing through a selected different filter will affect a second and different color modifier in a second and different layer which can be fixed thereby producing a multi-c0lor image.

6. The invention according to claim 5 in which three layers of color modifiers are provided.

7. The invention according to claim 6 in which the color modifier of the first layer is:

p Stearoylaminobenzoyl-(p-diethylaminophenylimino) aceto (m,m-dicarboxy) anilide;

the color modifier in the second layer is: twCyano-w-(pdiethylaminophenylimino) aceto (p-octadecenyl succinylamino) phenone; and

the color modifier in the third layer is: 2-carboxystearylamino 4 (p-diethylaminophenylim no) naphth0- qumone.

8. A method of making permanent color copies comprising:

(a) formingon a suitable base a layer of light-sensitive printing material according to claim 1; and

(b) exposing said layer imagewise to light.

References Cited UNITED STATES PATENTS 3,104,973 9/1963 Spraque et a1. 9648 OTHER REFERENCES Color Photography, Kirk-Othmer Encyclopedia of Chemical Technology, 2nd ed., vol. 5, pp. 828-830.

NORMAN G. TORCHIN, Primary Examiner WON H. LOUIE, JR., Assistant Examiner U.S. Cl. X.R. 9648 

